On Tuesday, one day after the footage was shown on TV, China's top quality and quarantine watchdog ordered an investigation into the food safety scandal.

Local public security in Shanghai was swift in detaining managers of the food company for further investigation while collecting evidence for examination.

And quality supervision officials have demanded the company suspend production immediately and recall the tainted steamed buns.

Sun Xiaofeng, Director of Bureau of Quality & Technical Supervision, said, "In the coming week, we will carefully examine all 225 registered food manufacturing companies in the area, to ensure residents eat safe and feel safe."

But such guarantees can hardly contain fears over food safety.

According to The Shanghai Daily, sales of steamed buns dropped across the city one day after the video aired.

Customers say they are worried that buns made by other companies may have the same problem. So they have chosen not to buy steamed buns for a while.

Officials say appropriate measures will be taken to prevent such things from happening again.

But it seems much has to be done before sales of steamed buns will pick up again.

And it is the same case with consumer's confidence.